1. Field of the Invention
The present invention relates to a password communication faculty of a facsimile apparatus for communicating with another station through a communication line.
2. Related Background Art
There are conventionally some networks which provide closed area connection as one of communication network services. Some communication terminal units such as facsimile apparatuses also provide closed area connection communication faculty using a password or the like between stations which can be interconnected. A password on such a station side is used as a convenient faculty for the user of a station when no closed area connection service is provided by the network, or when an extra charge is required to receive the service of the network.
The password communication faculty of a station is a faculty of communicating with only a partner apparatus which sends a password coincident with password information registered in the apparatus in advance. Many of currently available facsimile apparatuses based on the G3 and G4 recommendations of the CCITT have this faculty. Conventionally, however, standards of password communication are not defined in the above recommendations, so that each maker has realized the password communication faculty by a unique method, that is, a proprietary format. Therefore, password communication is conventionally enabled in communication between apparatuses made by the same maker. Users who intend password communication must purchase apparatuses of the same maker.
In a recent CCITT recommendation, however, a password communication signal is standardized to enable password communication between apparatuses made by different makers. Along with the standardization, users can also purchase apparatuses of different makers to utilize the closed area connection by password communication.
FIG. 5 is a view showing a closed area connection state wherein an apparatus having the standardized password faculty is defined as a "new type" and an apparatus having only the original password faculty of a maker is defined as an "old type" (defined from the viewpoint of a maker A). The reference numeral 5-1 denotes a network, a closed area group 5-2 is constituted by only conventional apparatuses made of the same maker. In this case, only the original password faculty of the maker can be used. In a closed area group 5-3 constituted by only apparatuses made by the same maker, the standardized password faculty can also be used. In a closed area group 5-4 constituted by apparatuses made of different makers, only the standardized password faculty can be used. In a closed area group 5-5 constituted by only apparatuses made of the same maker, apparatuses of a "new type" and an "old type" are simultaneously present. These closed area groups can be considered on the market. The users of each group are assumed to use a different method using the two passwords.
For example;
(1) Upon introduction of an apparatus of a "new type" and made of the maker A, the group 5-2 is required:
a. to use only the original password faculty of the maker A and not to use the standardized password faculty. PA0 a. to use only the original password faculty of the maker A and not to use the standardized password faculty; PA0 b. to use only the standardized password faculty and not to use the original password faculty of the maker A; PA0 c. to use both the original password faculty of the maker A and the standardized password faculty, thereby performing communication when one of the faculties is coincident; or PA0 d. to use both the original password faculty of the maker A and the standardized password faculty, thereby performing communication when both the faculties are coincident. PA0 a. to use only the standardized password faculty and not to use the original password faculty of the maker A; or PA0 b. to use both the original password faculty of the maker A and the standardized password faculty, thereby performing communication when one of the faculties is coincident. PA0 a. to use only the original password faculty of the maker A and not to use the standardized password faculty; or PA0 b. to use both the original password faculty of the maker A and the standardized password faculty, thereby performing communication when one of the faculties is coincident.
(2) Upon introduction of an apparatus of a "new type" and made of the maker A, the group 5-3 is required:
(3) Upon introduction of an apparatus of a "new type" and made by the maker A, the group 5-4 is required:
(4) Upon introduction of an apparatus of a "new type" and made by the maker A, the group 5-5 is required:
However, no conventional apparatus can cope with all these required conditions.